On the difficulities of real-time co-simulation

In a co-simulation, subsystems are coupled via their in- and outputs to simulate the overall system behaviour. The subsystems are modelled in their domain specfic simulation tools. The task changes if one coupled subsystem represents a real-time system. A real-time system which has to guarantees hard-real-time conditions influences the co-simulation concept: now the co-simulation also has to fulfill hard-real-time conditions. This type of co-simulation is called real-time co-simulation. The most important difference to a non-real-time co-simulation is the time correct overall simulation speed with respect to the involved real-time systems. To achieve this, all subsystems in form of non-real-time systems have to be synchronised to the involved real-time systems. The focus of this work lies on the problems that occur in a real-time co-simulation environment compared to a classical one. A concept to handle the additional problems is outlined and tested on an example real-time co-simulation

Reachability in Parametric Interval Markov Chains using Constraints

Parametric Interval Markov Chains (pIMCs) are a specification formalism that extend Markov Chains (MCs) and Interval Markov Chains (IMCs) by taking into account imprecision in the transition probability values: transitions in pIMCs are labeled with parametric intervals of probabilities. In this work, we study the difference between pIMCs and other Markov Chain abstractions models and investigate the two usual semantics for IMCs: once-and-for-all and at-every-step. In particular, we prove that both semantics agree on the maximal/minimal reachability probabilities of a given IMC. We then investigate solutions to several parameter synthesis problems in the context of pIMCs -- consistency, qualitative reachability and quantitative reachability -- that rely on constraint encodings. Finally, we propose a prototype implementation of our constraint encodings with promising results

Satisfiability of constraint specifications on XML documents

Jose Meseguer is one of the earliest contributors in the area of Algebraic Specification. In this paper, which we are happy to dedicate to him on the occasion of his 65th birthday, we use ideas and methods coming from that area with the aim of presenting an approach for the specification of the structure of classes of XML documents and for reasoning about them. More precisely, we specify the structure of documents using sets of constraints that are based on XPath and we present inference rules that are shown to define a sound and complete refutation procedure for checking satisfiability of a given specification using tableaux.Peer ReviewedPostprint (author's final draft

Theory of thermal spin-charge coupling in electronic systems

The interplay between spin transport and thermoelectricity offers several novel ways of generating, manipulating, and detecting nonequilibrium spin in a wide range of materials. Here we formulate a phenomenological model in the spirit of the standard model of electrical spin injection to describe the electronic mechanism coupling charge, spin, and heat transport and employ the model to analyze several different geometries containing ferromagnetic (F) and nonmagnetic (N) regions: F, F/N, and F/N/F junctions which are subject to thermal gradients. We present analytical formulas for the spin accumulation and spin current profiles in those junctions that are valid for both tunnel and transparent (as well as intermediate) contacts. For F/N junctions we calculate the thermal spin injection efficiency and the spin accumulation induced nonequilibrium thermopower. We find conditions for countering thermal spin effects in the N region with electrical spin injection. This compensating effect should be particularly useful for distinguishing electronic from other mechanisms of spin injection by thermal gradients. For F/N/F junctions we analyze the differences in the nonequilibrium thermopower (and chemical potentials) for parallel and antiparallel orientations of the F magnetizations, as evidence and a quantitative measure of the spin accumulation in N. Furthermore, we study the Peltier and spin Peltier effects in F/N and F/N/F junctions and present analytical formulas for the heat evolution at the interfaces of isothermal junctions.Comment: to be published in PRB (in press), 19 pages, 19 figure

Improving unbiased left/right training of rats and use of physostigmine to counteract scopolamine-induced short-term memory impairment

Rationale: The DNMTP task measures short-term / working memory uncontaminated by learning capacity,  spatial abilities, motor performance or general motivational and arousal factors. However, DNMTP training  of rats can take two months, and we aimed to reduce this. Methods: Two experiments were conducted on rats  in an operant DNMTP task. Improvements were made on the training procedure. The method was validated  by replicating the effect of scopolamine on working memory. The experiments also explored the influence  of physostigmine in reversing impairment induced by scopolamine. Thus in experiment 1, ten Lewis rats  were trained in an operant DNMTP task (1, 2, 4 and 8 s delay intervals) before 9 of them received vehicle,  scopolamine, saline or combinations of scopolamine and physostigmine. In experiment 2, ten Lewis rats (5  old and 5 young) were trained in the same task (1, 2, 4, 8 and 16 s delay intervals). There were six treatments:  0.05 mg/kg scopolamine, 0.1 mg/kg physostigmine or 0.15 mg/kg physostigmine, control involving  saline or involving no injection and no handling, and finally a combined treatment of 0.05mg/kg scopolamine  and 0.15 mg/kg physostigmine. In both experiments scopolamine significantly reduced correct  responses, nose-pokes and lever presses compaired to control conditions. Furthermore, in experiment 2,  there was insignificant difference between saline and combined scopolamine/physostigmine for correct  responses and for delay prior to pressing the sample lever. As expected, there was significant difference  between scopolamine and combined scopolamine/physostigmine for correct responses, for delay prior to  pressing the sample lever and for delay prior to pressing the non-matching lever. As a result, the animals  were ready for drug injection after 17 days from habituation and the method ensured that there were no dropouts  due to left or right lever preference. This is a shorter training period than previously thought necessary.  The brief training method was validated by replicating the effect of scopolamine on working memory.

Doxycycline Alters the Porcine Renal Proteome and Degradome during Hypothermic Machine Perfusion

Ischemia-reperfusion injury (IRI) is a hallmark for tissue injury in donation after circulatory death (DCD) kidneys. The implementation of hypothermic machine perfusion (HMP) provides a platform for improved preservation of DCD kidneys. Doxycycline administration has shown protective effects during IRI. Therefore, we explored the impact of doxycycline on proteolytic degradation mechanisms and the urinary proteome of perfused kidney grafts. Porcine kidneys underwent 30 min of warm ischemia, 24 h of oxygenated HMP (control/doxycycline) and 240 min of ex vivo reperfusion. A proteomic analysis revealed distinctive clustering profiles between urine samples collected at T15 min and T240 min. High-efficiency undecanal-based N-termini (HUNTER) kidney tissue degradomics revealed significantly more proteolytic activity in the control group at T-10. At T240, significantly more proteolytic activity was observed in the doxycycline group, indicating that doxycycline alters protein degradation during HMP. In conclusion, doxycycline administration during HMP led to significant proteomic and proteolytic differences and protective effects by attenuating urinary NGAL levels. Ultimately, we unraveled metabolic, and complement and coagulation pathways that undergo alterations during machine perfusion and that could be targeted to attenuate IRI induced injury

Separation of VUV/UV photons and reactive particles in the effluent of a He/O2 atmospheric pressure plasma jet

Cold atmospheric pressure plasmas can be used for treatment of living tissues or for inactivation of bacteria or biological macromolecules. The treatment is usually characterized by a combined effect of UV and VUV radiation, reactive species, and ions. This combination is usually beneficial for the effectiveness of the treatment but it makes the study of fundamental interaction mechanisms very difficult. Here we report on an effective separation of VUV/UV photons and heavy reactive species in the effluent of a micro scale atmospheric pressure plasma jet ($\mu$-APPJ). The separation is realized by an additional flow of helium gas under well-defined flow conditions, which deflects heavy particles in the effluent without affecting the VUV and UV photons. Both components of the effluent, the photons and the reactive species, can be used separately or in combination for sample treatment. The results of treatment of a model plasma polymer film and vegetative Bacillus subtilis and Escherichia coli cells are shown and discussed. A simple model of the He gas flow and reaction kinetics of oxygen atoms in the gas phase and at the surface is used to provide a better understanding of the processes in the plasma effluent. The new jet modification, called X-Jet for its appearance, will simplify the investigation of interaction mechanisms of atmospheric pressure plasmas with biological samples.Comment: 10 pages, 7 figures, submitted to Journal of Physics D: Applied Physic

The super-LHC

We review here the prospects of a long-term upgrade programme for the Large Hadron Collider (LHC), CERN laboratory's new proton-proton collider. The super-LHC, which is currently under evaluation and design, is expected to deliver of the order of ten times the statistics of the LHC. In addition to a non-technical summary of the principal physics arguments for the upgrade, I present a pedagogical introduction to the technological challenges on the accelerator and experimental fronts, and a review of the current status of the planning.Comment: To appear in Contemporary Physic

Logics for Unranked Trees: An Overview

Labeled unranked trees are used as a model of XML documents, and logical languages for them have been studied actively over the past several years. Such logics have different purposes: some are better suited for extracting data, some for expressing navigational properties, and some make it easy to relate complex properties of trees to the existence of tree automata for those properties. Furthermore, logics differ significantly in their model-checking properties, their automata models, and their behavior on ordered and unordered trees. In this paper we present a survey of logics for unranked trees